Electric protective system



I 1,642,405 pfi- 1927' M. BUCHHOLZ ELECTRIC PROTECTIVE SYSTEM Filed April 16, 1925 Patented Sept. '13, 1927.

UNITED STATES MAX BUCHHOLZ, or oA'ssEL, GEiimaNY.

nrno'rarc PROTECTIVE sys'rnm. v v

, Application filed April 16,1925, Serial No. 23,679, and in German y October G, 195M.

' My invention has reference to a method and means for protecting electric apparatus operating in an insulating liquid, such as oil transformers, oil switches, grounding throttling coils, resistances and the like, and it is one of the important objects of my invention to provide a device of very simple construction and great reliability, and adapted to operate before extensive 1n]uries to the apparatus to be protected can occur by sparking, overloading or other disturbances.

My invention is'particularly based on the fact that in the case of disturbances in the operation of the apparatus to'be protected or in the case of sparking or other irregularities of operation, or whenever such irregularities are imminent, as well as in the case of an ebullition or fermentation processes in th liquid, bubbles of gases of decomposition are formed which can operate a protective means, for instance an electric contact, either a working or a closed contact, which is adapted to switch out of circuit the apparatus to be protected, or which will operate an alarm or annunciator device indicating the disturbance, or which is adaptedto effect both kinds of operations. The gases formed 'by decomposition may influence the contacting means in diflerent ways;

According to the present invention I utilize the property of the gases or vapors generated from the insulating liquid and more especially insulating oil by decomposition or from other causes to be absorbed by certain substances, such as for instance platinum black. I can also utilize the property of these gases to chemically combine, with certain substances which need not be solids.

In consequence of such absorption or comfbination the weight of. the substances in question is increased correspondingly. This increase in weight can now be utilized for operating a mechanical or electric contact device arranged for operating a protective switch, alarm, annunciator device or the like adapted to cut out or to announce an unnormal condition of working of the transformer or other apparatus to be protected.

In the drawings aflixed to this specification and forming part thereof an arrangement embodying my invention is illustrated diagrammatically by way of example. Y In the drawings, a is a transformer vessel or container and b is the insulating oil or other liquid filling same and surrounding the e oil, serving as an insulating safety device inserted in it.

Instead of arranging the absorbing mass f PATENT orr clz, v

apparatus (not visible) to be protected, this insulating liquid developing gases or vapors containing for instance hydrogen, methane or the like whenever the normal operation of the apparatus surrounded by it is disturbed,

contact piece 72 capable of making and break-I ing contact with the other terminal of a protective circuit m comprising an oil switch, fuse, alarm or other annunciator device. To the other end of the lever 17 which extends above the nozzle 0 there is attached a mass 8 consisting of, covered with or containing platinum black or' some other substance capable of absorbing, occluding or chemically combining with one or several of the gases developed from the insulating liquid.

Obviously, when such gases are developed and escape through the nozzle 0, the will be absorbed by the mass, and the resu ting increase in weight will cause the mass 8 to descend, whereby the contact piece is is made toclose the circuit m and to operate the at one end of a lever, I may asvwell also arrange it within the container (1 above the liquid level, the connection between'it and the contact making device being established for instance by somesuspension means.

the releasing coil of an oil switch which in-' terrupts the endangered circuit. In the The circuit to be controlled by thecon- I tacts referred to may excite either directly or by the medium of an intermediate relay case of apparatus the circuit of which does not include an oil switch, asfrequently occurs, for instance in the cases of transformers mounted in the field at wide distances apart, 'other provisions should be made for the purposes of this invention.

Beside the form of construction herein shown and described, the invention is susceptible of a variety of other modifications and forms of application of, the mind le of my invention all of which operate su stantially in a similar manner. The means of connecting thecontacting device with the releasing circuit and the switching means are Open to changes and alterationsv without any material importance for th eoperation of the apparatus according to my invention which in its broad aspects comprises the operation of safety devices for electric apfications Without deviating from the spirit of my invention as set forth in the claims.

In the claims the term gases is meant t comprise also vapors and fumes.

I claim 1. Protective system for liquid-insulated electric apparatus, comprising a supply of insulating liquid, which, when decomposed,

develops gases containing an absorbable gas, a substance disposed near said liquid which is capable of absorbing gases developed from said liquid and protective means conaeoe nected with and rendered operative by an increase in weight of said substance.

2. Protective system for liquid-insulated electric apparatus, comprising a supply of insulating liquid, which, when decomposed, develops gases containing an absorbable gas, a protective circuit, a balanced contact lever above said liquid and a mass connected with the free arm of said lever capableof absorbing gases developed from said liquid resulting in shifting said lever and afiecting the operative condition of said circuit.

3. The method of controlling abnormal Working conditions of liquid insulated apparatus which comprises subjecting a substance adapted to absorb gases to contact with gases develo ed in the insulating liquid in consequence 0 abnormal conditions and causing the resultant increase in the Weight of such substance to vary the operative condition or protective means.

lln testimony whereof I afix my signature.

MAX BUCHHOLZ. 

